/**
 *  Copyright (c) 1997-2013, www.tinygroup.org (luo_guo@icloud.com).
 *
 *  Licensed under the GPL, Version 3.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *       http://www.gnu.org/licenses/gpl.html
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.tinygroup.commons.tools;

import org.tinygroup.commons.collection.IntHashMap;

import java.util.Map;

import static org.tinygroup.commons.tools.CollectionUtil.createHashMap;



/**
 * 代表HTML和XML的实体定义。
 * <p>
 * 该类采用一个hash表和lookup查找表相结合的算法，确保搜索entities的性能。
 * </p>
 *
 * @author renhui
 * @see <a
 *      href="http://hotwired.lycos.com/webmonkey/reference/special_characters/">ISO
 *      Entities</a>
 * @see <a href="http://www.w3.org/TR/REC-html32#latin1">HTML 3.2 Character
 *      Entities for ISO Latin-1</a>
 * @see <a href="http://www.w3.org/TR/REC-html40/sgml/entities.html">HTML 4.0
 *      Character entity references</a>
 * @see <a href="http://www.w3.org/TR/html401/charset.html#h-5.3">HTML 4.01
 *      Character References</a>
 * @see <a href="http://www.w3.org/TR/html401/charset.html#code-position">HTML
 *      4.01 Code positions</a>
 */
public class Entities {
    /** 基本实体定义。 */
    private static final String[][] BASIC_SET = { { "quot", "34" }, // " - double-quote
                                                  { "amp", "38" }, // & - ampersand
                                                  { "lt", "60" }, // < - less-than
                                                  { "gt", "62" }, // > - greater-than
    };

    /** XML省略语。 */
    private static final String[][] APOS_SET = { { "apos", "39" }, // XML apostrophe
    };

    /** 8859-1实体定义。 */
    private static final String[][] ISO_8859_1_SET = { { "nbsp", "160" }, // non-breaking space
                                                       { "iexcl", "161" }, // inverted exclamation mark
                                                       { "cent", "162" }, // cent sign
                                                       { "pound", "163" }, // pound sign
                                                       { "curren", "164" }, // currency sign
                                                       { "yen", "165" }, // yen sign = yuan sign
                                                       { "brvbar", "166" }, // broken bar = broken vertical bar
                                                       { "sect", "167" }, // section sign
                                                       { "uml", "168" }, // diaeresis = spacing diaeresis
                                                       { "copy", "169" }, // ? - copyright sign
                                                       { "ordf", "170" }, // feminine ordinal indicator
                                                       { "laquo", "171" }, // left-pointing double angle quotation mark = left pointing guillemet
                                                       { "not", "172" }, // not sign
                                                       { "shy", "173" }, // soft hyphen = discretionary hyphen
                                                       { "reg", "174" }, // ? - registered trademark sign
                                                       { "macr", "175" }, // macron = spacing macron = overline = APL overbar
                                                       { "deg", "176" }, // degree sign
                                                       { "plusmn", "177" }, // plus-minus sign = plus-or-minus sign
                                                       { "sup2", "178" }, // superscript two = superscript digit two = squared
                                                       { "sup3", "179" }, // superscript three = superscript digit three = cubed
                                                       { "acute", "180" }, // acute accent = spacing acute
                                                       { "micro", "181" }, // micro sign
                                                       { "para", "182" }, // pilcrow sign = paragraph sign
                                                       { "middot", "183" }, // middle dot = Georgian comma = Greek middle dot
                                                       { "cedil", "184" }, // cedilla = spacing cedilla
                                                       { "sup1", "185" }, // superscript one = superscript digit one
                                                       { "ordm", "186" }, // masculine ordinal indicator
                                                       { "raquo", "187" }, // right-pointing double angle quotation mark = right pointing guillemet
                                                       { "frac14", "188" }, // vulgar fraction one quarter = fraction one quarter
                                                       { "frac12", "189" }, // vulgar fraction one half = fraction one half
                                                       { "frac34", "190" }, // vulgar fraction three quarters = fraction three quarters
                                                       { "iquest", "191" }, // inverted question mark = turned question mark
                                                       { "Agrave", "192" }, // ? - uppercase A, grave accent
                                                       { "Aacute", "193" }, // ? - uppercase A, acute accent
                                                       { "Acirc", "194" }, // ? - uppercase A, circumflex accent
                                                       { "Atilde", "195" }, // ? - uppercase A, tilde
                                                       { "Auml", "196" }, // ? - uppercase A, umlaut
                                                       { "Aring", "197" }, // ? - uppercase A, ring
                                                       { "AElig", "198" }, // ? - uppercase AE
                                                       { "Ccedil", "199" }, // ? - uppercase C, cedilla
                                                       { "Egrave", "200" }, // ? - uppercase E, grave accent
                                                       { "Eacute", "201" }, // ? - uppercase E, acute accent
                                                       { "Ecirc", "202" }, // ? - uppercase E, circumflex accent
                                                       { "Euml", "203" }, // ? - uppercase E, umlaut
                                                       { "Igrave", "204" }, // ? - uppercase I, grave accent
                                                       { "Iacute", "205" }, // ? - uppercase I, acute accent
                                                       { "Icirc", "206" }, // ? - uppercase I, circumflex accent
                                                       { "Iuml", "207" }, // ? - uppercase I, umlaut
                                                       { "ETH", "208" }, // ? - uppercase Eth, Icelandic
                                                       { "Ntilde", "209" }, // ? - uppercase N, tilde
                                                       { "Ograve", "210" }, // ? - uppercase O, grave accent
                                                       { "Oacute", "211" }, // ? - uppercase O, acute accent
                                                       { "Ocirc", "212" }, // ? - uppercase O, circumflex accent
                                                       { "Otilde", "213" }, // ? - uppercase O, tilde
                                                       { "Ouml", "214" }, // ? - uppercase O, umlaut
                                                       { "times", "215" }, // multiplication sign
                                                       { "Oslash", "216" }, // ? - uppercase O, slash
                                                       { "Ugrave", "217" }, // ? - uppercase U, grave accent
                                                       { "Uacute", "218" }, // ? - uppercase U, acute accent
                                                       { "Ucirc", "219" }, // ? - uppercase U, circumflex accent
                                                       { "Uuml", "220" }, // ? - uppercase U, umlaut
                                                       { "Yacute", "221" }, // ? - uppercase Y, acute accent
                                                       { "THORN", "222" }, // ? - uppercase THORN, Icelandic
                                                       { "szlig", "223" }, // ? - lowercase sharps, German
                                                       { "agrave", "224" }, // ? - lowercase a, grave accent
                                                       { "aacute", "225" }, // ? - lowercase a, acute accent
                                                       { "acirc", "226" }, // ? - lowercase a, circumflex accent
                                                       { "atilde", "227" }, // ? - lowercase a, tilde
                                                       { "auml", "228" }, // ? - lowercase a, umlaut
                                                       { "aring", "229" }, // ? - lowercase a, ring
                                                       { "aelig", "230" }, // ? - lowercase ae
                                                       { "ccedil", "231" }, // ? - lowercase c, cedilla
                                                       { "egrave", "232" }, // ? - lowercase e, grave accent
                                                       { "eacute", "233" }, // ? - lowercase e, acute accent
                                                       { "ecirc", "234" }, // ? - lowercase e, circumflex accent
                                                       { "euml", "235" }, // ? - lowercase e, umlaut
                                                       { "igrave", "236" }, // ? - lowercase i, grave accent
                                                       { "iacute", "237" }, // ? - lowercase i, acute accent
                                                       { "icirc", "238" }, // ? - lowercase i, circumflex accent
                                                       { "iuml", "239" }, // ? - lowercase i, umlaut
                                                       { "eth", "240" }, // ? - lowercase eth, Icelandic
                                                       { "ntilde", "241" }, // ? - lowercase n, tilde
                                                       { "ograve", "242" }, // ? - lowercase o, grave accent
                                                       { "oacute", "243" }, // ? - lowercase o, acute accent
                                                       { "ocirc", "244" }, // ? - lowercase o, circumflex accent
                                                       { "otilde", "245" }, // ? - lowercase o, tilde
                                                       { "ouml", "246" }, // ? - lowercase o, umlaut
                                                       { "divide", "247" }, // division sign
                                                       { "oslash", "248" }, // ? - lowercase o, slash
                                                       { "ugrave", "249" }, // ? - lowercase u, grave accent
                                                       { "uacute", "250" }, // ? - lowercase u, acute accent
                                                       { "ucirc", "251" }, // ? - lowercase u, circumflex accent
                                                       { "uuml", "252" }, // ? - lowercase u, umlaut
                                                       { "yacute", "253" }, // ? - lowercase y, acute accent
                                                       { "thorn", "254" }, // ? - lowercase thorn, Icelandic
                                                       { "yuml", "255" }, // ? - lowercase y, umlaut
    };

    /** HTML 4.0实体定义（http://www.w3.org/TR/REC-html40/sgml/entities.html）。 */
    private static final String[][] HTML40_SET = { { "fnof", "402" }, // latin small f with hook = function= florin, U+0192 ISOtech
                                                   { "Alpha", "913" }, // greek capital letter alpha, U+0391
                                                   { "Beta", "914" }, // greek capital letter beta, U+0392
                                                   { "Gamma", "915" }, // greek capital letter gamma,U+0393 ISOgrk3
                                                   { "Delta", "916" }, // greek capital letter delta,U+0394 ISOgrk3
                                                   { "Epsilon", "917" }, // greek capital letter epsilon, U+0395
                                                   { "Zeta", "918" }, // greek capital letter zeta, U+0396
                                                   { "Eta", "919" }, // greek capital letter eta, U+0397
                                                   { "Theta", "920" }, // greek capital letter theta,U+0398 ISOgrk3
                                                   { "Iota", "921" }, // greek capital letter iota, U+0399
                                                   { "Kappa", "922" }, // greek capital letter kappa, U+039A
                                                   { "Lambda", "923" }, // greek capital letter lambda,U+039B ISOgrk3
                                                   { "Mu", "924" }, // greek capital letter mu, U+039C
                                                   { "Nu", "925" }, // greek capital letter nu, U+039D
                                                   { "Xi", "926" }, // greek capital letter xi, U+039E ISOgrk3
                                                   { "Omicron", "927" }, // greek capital letter omicron, U+039F
                                                   { "Pi", "928" }, // greek capital letter pi, U+03A0 ISOgrk3
                                                   { "Rho", "929" }, // greek capital letter rho, U+03A1
                                                   { "Sigma", "931" }, // greek capital letter sigma,U+03A3 ISOgrk3
                                                   { "Tau", "932" }, // greek capital letter tau, U+03A4
                                                   { "Upsilon", "933" }, // greek capital letter upsilon,U+03A5 ISOgrk3
                                                   { "Phi", "934" }, // greek capital letter phi,U+03A6 ISOgrk3
                                                   { "Chi", "935" }, // greek capital letter chi, U+03A7
                                                   { "Psi", "936" }, // greek capital letter psi,U+03A8 ISOgrk3
                                                   { "Omega", "937" }, // greek capital letter omega,U+03A9 ISOgrk3
                                                   { "alpha", "945" }, // greek small letter alpha,U+03B1 ISOgrk3
                                                   { "beta", "946" }, // greek small letter beta, U+03B2 ISOgrk3
                                                   { "gamma", "947" }, // greek small letter gamma,U+03B3 ISOgrk3
                                                   { "delta", "948" }, // greek small letter delta,U+03B4 ISOgrk3
                                                   { "epsilon", "949" }, // greek small letter epsilon,U+03B5 ISOgrk3
                                                   { "zeta", "950" }, // greek small letter zeta, U+03B6 ISOgrk3
                                                   { "eta", "951" }, // greek small letter eta, U+03B7 ISOgrk3
                                                   { "theta", "952" }, // greek small letter theta,U+03B8 ISOgrk3
                                                   { "iota", "953" }, // greek small letter iota, U+03B9 ISOgrk3
                                                   { "kappa", "954" }, // greek small letter kappa,U+03BA ISOgrk3
                                                   { "lambda", "955" }, // greek small letter lambda,U+03BB ISOgrk3
                                                   { "mu", "956" }, // greek small letter mu, U+03BC ISOgrk3
                                                   { "nu", "957" }, // greek small letter nu, U+03BD ISOgrk3
                                                   { "xi", "958" }, // greek small letter xi, U+03BE ISOgrk3
                                                   { "omicron", "959" }, // greek small letter omicron, U+03BF NEW
                                                   { "pi", "960" }, // greek small letter pi, U+03C0 ISOgrk3
                                                   { "rho", "961" }, // greek small letter rho, U+03C1 ISOgrk3
                                                   { "sigmaf", "962" }, // greek small letter final sigma,U+03C2 ISOgrk3
                                                   { "sigma", "963" }, // greek small letter sigma,U+03C3 ISOgrk3
                                                   { "tau", "964" }, // greek small letter tau, U+03C4 ISOgrk3
                                                   { "upsilon", "965" }, // greek small letter upsilon,U+03C5 ISOgrk3
                                                   { "phi", "966" }, // greek small letter phi, U+03C6 ISOgrk3
                                                   { "chi", "967" }, // greek small letter chi, U+03C7 ISOgrk3
                                                   { "psi", "968" }, // greek small letter psi, U+03C8 ISOgrk3
                                                   { "omega", "969" }, // greek small letter omega,U+03C9 ISOgrk3
                                                   { "thetasym", "977" }, // greek small letter theta symbol,U+03D1 NEW
                                                   { "upsih", "978" }, // greek upsilon with hook symbol,U+03D2 NEW
                                                   { "piv", "982" }, // greek pi symbol, U+03D6 ISOgrk3
                                                   { "bull", "8226" }, // bullet = black small circle,U+2022 ISOpub
                                                   { "hellip", "8230" }, // horizontal ellipsis = three dot leader,U+2026 ISOpub
                                                   { "prime", "8242" }, // prime = minutes = feet, U+2032 ISOtech
                                                   { "Prime", "8243" }, // double prime = seconds = inches,U+2033 ISOtech
                                                   { "oline", "8254" }, // overline = spacing overscore,U+203E NEW
                                                   { "frasl", "8260" }, // fraction slash, U+2044 NEW
                                                   { "weierp", "8472" }, // script capital P = power set= Weierstrass p, U+2118 ISOamso
                                                   { "image", "8465" }, // blackletter capital I = imaginary part,U+2111 ISOamso
                                                   { "real", "8476" }, // blackletter capital R = real part symbol,U+211C ISOamso
                                                   { "trade", "8482" }, // trade mark sign, U+2122 ISOnum
                                                   { "alefsym", "8501" }, // alef symbol = first transfinite cardinal,U+2135 NEW
                                                   { "larr", "8592" }, // leftwards arrow, U+2190 ISOnum
                                                   { "uarr", "8593" }, // upwards arrow, U+2191 ISOnum
                                                   { "rarr", "8594" }, // rightwards arrow, U+2192 ISOnum
                                                   { "darr", "8595" }, // downwards arrow, U+2193 ISOnum
                                                   { "harr", "8596" }, // left right arrow, U+2194 ISOamsa
                                                   { "crarr", "8629" }, // downwards arrow with corner leftwards= carriage return, U+21B5 NEW
                                                   { "lArr", "8656" }, // leftwards double arrow, U+21D0 ISOtech
                                                   { "uArr", "8657" }, // upwards double arrow, U+21D1 ISOamsa
                                                   { "rArr", "8658" }, // rightwards double arrow,U+21D2 ISOtech
                                                   { "dArr", "8659" }, // downwards double arrow, U+21D3 ISOamsa
                                                   { "hArr", "8660" }, // left right double arrow,U+21D4 ISOamsa
                                                   { "forall", "8704" }, // for all, U+2200 ISOtech
                                                   { "part", "8706" }, // partial differential, U+2202 ISOtech
                                                   { "exist", "8707" }, // there exists, U+2203 ISOtech
                                                   { "empty", "8709" }, // empty set = null set = diameter,U+2205 ISOamso
                                                   { "nabla", "8711" }, // nabla = backward difference,U+2207 ISOtech
                                                   { "isin", "8712" }, // element of, U+2208 ISOtech
                                                   { "notin", "8713" }, // not an element of, U+2209 ISOtech
                                                   { "ni", "8715" }, // contains as member, U+220B ISOtech
                                                   { "prod", "8719" }, // n-ary product = product sign,U+220F ISOamsb
                                                   { "sum", "8721" }, // n-ary sumation, U+2211 ISOamsb
                                                   { "minus", "8722" }, // minus sign, U+2212 ISOtech
                                                   { "lowast", "8727" }, // asterisk operator, U+2217 ISOtech
                                                   { "radic", "8730" }, // square root = radical sign,U+221A ISOtech
                                                   { "prop", "8733" }, // proportional to, U+221D ISOtech
                                                   { "infin", "8734" }, // infinity, U+221E ISOtech
                                                   { "ang", "8736" }, // angle, U+2220 ISOamso
                                                   { "and", "8743" }, // logical and = wedge, U+2227 ISOtech
                                                   { "or", "8744" }, // logical or = vee, U+2228 ISOtech
                                                   { "cap", "8745" }, // intersection = cap, U+2229 ISOtech
                                                   { "cup", "8746" }, // union = cup, U+222A ISOtech
                                                   { "int", "8747" }, // integral, U+222B ISOtech
                                                   { "there4", "8756" }, // therefore, U+2234 ISOtech
                                                   { "sim", "8764" }, // tilde operator = varies with = similar to,U+223C ISOtech
                                                   { "cong", "8773" }, // approximately equal to, U+2245 ISOtech
                                                   { "asymp", "8776" }, // almost equal to = asymptotic to,U+2248 ISOamsr
                                                   { "ne", "8800" }, // not equal to, U+2260 ISOtech
                                                   { "equiv", "8801" }, // identical to, U+2261 ISOtech
                                                   { "le", "8804" }, // less-than or equal to, U+2264 ISOtech
                                                   { "ge", "8805" }, // greater-than or equal to,U+2265 ISOtech
                                                   { "sub", "8834" }, // subset of, U+2282 ISOtech
                                                   { "sup", "8835" }, // superset of, U+2283 ISOtech
                                                   { "sube", "8838" }, // subset of or equal to, U+2286 ISOtech
                                                   { "supe", "8839" }, // superset of or equal to,U+2287 ISOtech
                                                   { "oplus", "8853" }, // circled plus = direct sum,U+2295 ISOamsb
                                                   { "otimes", "8855" }, // circled times = vector product,U+2297 ISOamsb
                                                   { "perp", "8869" }, // up tack = orthogonal to = perpendicular,U+22A5 ISOtech
                                                   { "sdot", "8901" }, // dot operator, U+22C5 ISOamsb
                                                   { "lceil", "8968" }, // left ceiling = apl upstile,U+2308 ISOamsc
                                                   { "rceil", "8969" }, // right ceiling, U+2309 ISOamsc
                                                   { "lfloor", "8970" }, // left floor = apl downstile,U+230A ISOamsc
                                                   { "rfloor", "8971" }, // right floor, U+230B ISOamsc
                                                   { "lang", "9001" }, // left-pointing angle bracket = bra,U+2329 ISOtech
                                                   { "rang", "9002" }, // right-pointing angle bracket = ket,U+232A ISOtech
                                                   { "loz", "9674" }, // lozenge, U+25CA ISOpub
                                                   { "spades", "9824" }, // black spade suit, U+2660 ISOpub
                                                   { "clubs", "9827" }, // black club suit = shamrock,U+2663 ISOpub
                                                   { "hearts", "9829" }, // black heart suit = valentine,U+2665 ISOpub
                                                   { "diams", "9830" }, // black diamond suit, U+2666 ISOpub
                                                   { "OElig", "338" }, // latin capital ligature OE,U+0152 ISOlat2
                                                   { "oelig", "339" }, // latin small ligature oe, U+0153 ISOlat2
                                                   { "Scaron", "352" }, // latin capital letter S with caron,U+0160 ISOlat2
                                                   { "scaron", "353" }, // latin small letter s with caron,U+0161 ISOlat2
                                                   { "Yuml", "376" }, // latin capital letter Y with diaeresis,U+0178 ISOlat2
                                                   { "circ", "710" }, // modifier letter circumflex accent,U+02C6 ISOpub
                                                   { "tilde", "732" }, // small tilde, U+02DC ISOdia
                                                   { "ensp", "8194" }, // en space, U+2002 ISOpub
                                                   { "emsp", "8195" }, // em space, U+2003 ISOpub
                                                   { "thinsp", "8201" }, // thin space, U+2009 ISOpub
                                                   { "zwnj", "8204" }, // zero width non-joiner,U+200C NEW RFC 2070
                                                   { "zwj", "8205" }, // zero width joiner, U+200D NEW RFC 2070
                                                   { "lrm", "8206" }, // left-to-right mark, U+200E NEW RFC 2070
                                                   { "rlm", "8207" }, // right-to-left mark, U+200F NEW RFC 2070
                                                   { "ndash", "8211" }, // en dash, U+2013 ISOpub
                                                   { "mdash", "8212" }, // em dash, U+2014 ISOpub
                                                   { "lsquo", "8216" }, // left single quotation mark,U+2018 ISOnum
                                                   { "rsquo", "8217" }, // right single quotation mark,U+2019 ISOnum
                                                   { "sbquo", "8218" }, // single low-9 quotation mark, U+201A NEW
                                                   { "ldquo", "8220" }, // left double quotation mark,U+201C ISOnum
                                                   { "rdquo", "8221" }, // right double quotation mark,U+201D ISOnum
                                                   { "bdquo", "8222" }, // double low-9 quotation mark, U+201E NEW
                                                   { "dagger", "8224" }, // dagger, U+2020 ISOpub
                                                   { "Dagger", "8225" }, // double dagger, U+2021 ISOpub
                                                   { "permil", "8240" }, // per mille sign, U+2030 ISOtech
                                                   { "lsaquo", "8249" }, // single left-pointing angle quotation mark,U+2039 ISO proposed
                                                   { "rsaquo", "8250" }, // single right-pointing angle quotation mark,U+203A ISO proposed
                                                   { "euro", "8364" }, // euro sign, U+20AC NEW
    };

    /** XML规范定义的实体集。 */
    public static final Entities XML;

    /** HTML 3.2规范定义的实体集。 */
    public static final Entities HTML32;

    /** HTML 4.0规范定义的实体集。 */
    public static final Entities HTML40;

    /** HTML 4.0规范定义的实体集，加上对单引号的转义，以增加HTML安全性。 */
    public static final Entities HTML40_MODIFIED;

    /**
     * 初始化预定义的实体集。
     */
    static {
        XML = new Entities();
        XML.addEntities(BASIC_SET);
        XML.addEntities(APOS_SET);

        HTML32 = new Entities();
        HTML32.addEntities(BASIC_SET);
        HTML32.addEntities(ISO_8859_1_SET);

        HTML40 = new Entities();
        HTML40.addEntities(BASIC_SET);
        HTML40.addEntities(ISO_8859_1_SET);
        HTML40.addEntities(HTML40_SET);

        HTML40_MODIFIED = new Entities(HTML40);
        HTML40_MODIFIED.addEntity("#39", 39);
    }

    /** 快速查找表的大小。 */
    private static final int LOOKUP_TABLE_SIZE = 256;

    private Map<String, Integer> entityNameToValue = createHashMap();
    private IntHashMap<String>   entityValueToName = new IntHashMap<String>();
    private String[] lookupTable;

    public Entities() {
    }

    /** 复制entities。 */
    public Entities(Entities entities) {
        for (Map.Entry<String, Integer> entry : entities.entityNameToValue.entrySet()) {
            addEntity(entry.getKey(), entry.getValue());
        }
    }

    /**
     * 添加一组entities。
     *
     * @param entitySet entity定义数组
     */
    public void addEntities(String[][] entitySet) {
        for (int i = 0; i < entitySet.length; ++i) {
            addEntity(entitySet[i][0], Integer.parseInt(entitySet[i][1]));
        }
    }

    /**
     * 添加一个entity。
     *
     * @param name  entity名称
     * @param value entity值
     */
    public void addEntity(String name, int value) {
        entityNameToValue.put(name, new Integer(value));
        entityValueToName.put(value, name);

        // 更新查找表
        if (value < LOOKUP_TABLE_SIZE && lookupTable != null) {
            lookupTable[value] = name;
        }
    }

    /**
     * 取得指定值对应的entity名称。
     *
     * @param value entity的值
     * @return entity的名称
     */
    public String getEntityName(int value) {
        if (value < LOOKUP_TABLE_SIZE) {
            // 创建快速查找表
            if (lookupTable == null) {
                lookupTable = new String[LOOKUP_TABLE_SIZE];

                for (int i = 0; i < LOOKUP_TABLE_SIZE; ++i) {
                    lookupTable[i] = entityValueToName.get(i);
                }
            }

            return lookupTable[value];
        }

        return entityValueToName.get(value);
    }

    /**
     * 取得指定entity名称对应的entity值。
     *
     * @param name entity的名称
     * @return entity的值
     */
    public int getEntityValue(String name) {
        Object value = entityNameToValue.get(name);

        if (value == null) {
            return -1;
        }

        return ((Integer) value).intValue();
    }
}
